I look forward to seeing that. That is the same set up I am looking at. I bought this car as a commuter since I have a long daily drive. That said, I am not looking to ever go wider than a 195 and have to run tires that I can get reasonable mileage out of so I think a x7 +35 works best for my needs.
What size/offset 6ul's are you planning on?
If I take your post for face value, I think you may have some things confused or may have been mislead to think that the so called Section Width measurement of your tire directly reflects what contacts the ground when properly inflated. In this case we're talking about 185mm section width of our stock tire with an aspect ratio of 55 compared to lets say my tire at 205 section width and a 50 aspect ratio.
Although your section width does increase some of your contact patch, it's not as bad as you might think.
For example, our stock steelie tires 185/55R15 will give us an effective 101.75mm Section width. (Found by 185 x .55 = 101.75)
Whereas my new tires 205/50R15 will give us an effective 102.5 Section Width (found by 205 x .55 = 102.5)
The difference is pretty miniscule as you can see, at a total increase in section width of 0.75mm. At 100MPH the difference in your speedo would be 100.26MPH
At 195/50 your speed will be slower than your speedo at 59.13MPH when your speedo reads 60, or 98.55 when your speedo reads 100mph as comparison.
Because you've kept everything pretty much the same, your gas mileage won't and shouldn't really fluctuate, and if you're worried about mileage warranty on your tires, most companies warranty their 55 aspect ratio and under tires at 40,000-50,000 miles. Only when you increase to 60-65 aspect ratio do you get a real increase to 60,000 miles+.
The width of the rims you choose won't have an effect on how your tires will perform or contact the ground unless you undersize or oversize according to the manufacturers recommendations and or under/overinflate your tires.. They'll usually have like...Recommend install of this tire on a 6-7.5 inch width rim for optimal performance.